-LRB- CNN -RRB- -- A Boston-area man , who was planning to kidnap children , lock them in a basement dungeon , rape and eat them , should be imprisoned for at least 27 years , federal authorities said in court documents filed this week .

Geoffrey Portway pleaded guilty in May to distribution and possession of child pornography and solicitation to commit a crime of violence , according to court documents . He is scheduled to be sentenced on September 17 .

`` Portway has pled guilty to some of the most vile and heinous crimes known to our society , '' federal prosecutors wrote in a sentencing recommendation .

But a lawyer for the 40-year-old defendant told CNN his client `` lived in a fantasy world '' and there was no evidence he harmed any child .

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Portway went by the moniker `` Fat Longpig '' during his online chats , according to court documents . It was these chats that put Portway on the radar screen of police .

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When his home in Worcester was searched last year , authorities found tens of thousands of computer images and videos of child pornography and 4,500 exchanges of child pornography between Portway and the people he chatted with online . The images included children being cooked and prepared to be eaten , court documents said . Those photographs are sealed .

Authorities also found a locked basement , court documents show . Photos taken the day of Portway 's arrest , and released by prosecutors , show a narrow wooden staircase leading downstairs to a soundproof room .

It was furnished with a metal cage with a circular hole for feeding , a rusted and worn steel-topped table , as well as multiple kinds of metal bondage equipment . A child-sized coffin made of plywood was found on the floor nearby .

Portway 's lawyer , Richard J. Sweeney , told CNN that Tuesday 's sentencing hearing will be `` the proper time to address all the issues addressed by the government . '' But he added , `` There 's no evidence at all of Geoffrey being involved with any child or harming any child . ''

`` Geoffrey lived in a fantasy world where he did live-action role playing , did things online unrelated to child porn and cannibalism . A lot of the chats that he had were , in his mind , fantasy , '' Sweeney said . `` When they went out to the other people he was talking to , these other people actually had kids they were taking photos of . Geoffrey did not have any kids he had abducted , though he certainly talked about it . ''

Photographs reviewed by CNN show handcuffs , rope intended for bondage , mouth gags , and castration tools . A large box of frozen raw chicken , near a handful of disposable scalpels , was photographed by investigators near two industrial-sized freezers .

In the kitchen , a jug of bleach was seen by the doorway , while a red child-sized `` onesie '' lay on the countertop , amid snacks and disposable syringes . A butcher kit containing plastic gloves , multiple knives and other items was photographed in the sink .

Among a DVD collection , the documents show , were titles such as `` Human Beast , '' `` Hansel and Gretel , '' `` The Real Cannibal Holocaust , '' `` The Genesis Children , '' `` Cannibal the Musical , '' and `` Cannibal Ferox , '' a film with the tagline `` Make them die slowly . ''

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Online chats , seized by police , showed Portway call his basement a `` dungeon '' where he intended to `` keep kidnapped children while he sexually abused them and as a place to eventually murder and cannibalize the children . ''

Two other men who chatted with Portway have already been convicted .

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One was a puppeteer who , authorities say , plotted with Portway to kidnap children the puppeteer knew from his work at a local Florida church .

`` Portway 's collection is truly chilling and demonstrates a real risk based upon which the Court should sentence Portway to a substantial term of years in order to protect the public , '' prosecutors said .

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CNN 's Deborah Feyerick and Rande Iaboni contributed to this report .

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Geoffrey Portway `` lived in a fantasy world , '' his lawyer says

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Prosecutors say Portway has admitted to `` vile and heinous crimes ''

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He is scheduled to be sentenced on September 17

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Investigators found a soundproof room with a metal cage in his basement , court documents show